![Simulated climates and observables for CO2-rich planets near the outer edge of the habitable zone. The illustration on the right depicts a potentially habitable world orbiting a Sun-like star. The teal point in the lower left section of the panel marks the orbital location of such a planet within the OHZ, and the corresponding reflected light spectrum that could be observed via direct imaging is shown in teal in the middle, left section of the panel. The upper left section of the panel shows an illustration of the same planet in a globally frozen state located just beyond the habitable zone. Its orbital position (lower left) and reflected light spectrum (middle) are shown in white. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/High-CO2.png?resize=1200%2C721&ssl=1)
[astro-ph.EP] The habitable zone (HZ) is a fundamental concept used to guide our search for temperate exoplanets with stable surface liquid water that would sustain remotely detectable biosignatures.
Exoplanets, -moons, -comets
Posted inExoplanets, -moons, -comets
Detecting Extragalactic Exoplanets With Fast Radio Burst Nanolensing
[astro-ph.EP] Fast Radio Bursts (FRBs) are spatially and temporally compact sources at cosmological distances. As background sources, they will be uniquely sensitive to the gravitational lensing of exoplanets outside of […]
![SpeX SXD spectrum of TOI-6981. The target spectrum (red) is shown alongside that of the M3.5V standard Luyten’s Star (grey), offset vertically for clarity. Regions of strong telluric absorption are shaded, and strong M-dwarf spectral features are indicated. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/TOI-6981.png?resize=1200%2C718&ssl=1)
Posted inExoplanets, -moons, -comets
TOI-6981 b: A Transiting Sub-Neptune At The Water Ice Line
[astro-ph.EP] We present TOI-6981 b, a cold (Teq= 170.0 +/-4.5 K, assuming an Earth-like albedo) sub-Neptune (Rb=2.40+/-0.10 R⊕) on a 60.8 day orbit around around its M4-type host star (R*=0.304 […]
![Final semi-major axes and masses for all objects produced in simulations with regular disks. The left panel shows objects produced in disks with low C/O ratios and the right one shows planets in high C/O ratio disks. The dash-dotted line shows the initial mass of planestesimals in our simulations while the dotted line shows the initial mass of planetary embryos. We consider planets to be anything at or above the initial embryo mass, fragments to be anything below the initial planetesimal mass, and planetesimals to be any object at or above the initial planetesimal mass but below the initial embryo mass. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Correlations.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
Correlations Between The Carbon-to-Oxygen Ratio and the Orbital and Physical Properties of Exoplanets
[astro-ph.EP] Studies suggest that protoplanetary disks around stars with high carbon-to-oxygen (C/O) ratios can produce terrestrial planets with carbon-dominated compositions instead of silicon-dominated ones.
![Chemical clock relations for planet-hosting solar analogs, showing abundance ratios as a function of stellar age for [Y/Mg], [Y/Al], [Ba/Mg], [Ba/Al], [Sr/Mg], and [Y/(Mg+Al)/2]. Data points are color-coded by metallicity ([Fe/H]). Black lines show best-fit linear relations derived using Deming regression, accounting for uncertainties in both variables, and shaded regions indicate 1σ confidence intervals. All abundance ratios show statistically significant correlations with stellar age. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Planets-Around.png?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
Planets Around Solar Twins/Analogs (PASTA) III: Chemical Clock Relations in Planet-Hosting Solar Analogs
[astro-ph.EP] Context. Abundance ratios between elements synthesized on different nucleosynthetic timescales provide empirical chemical clocks for estimating stellar ages, but robust calibrations require homogeneous samples with precise stellar parameters and […]
Posted inExoplanets, -moons, -comets
The IAC Presents The SELF Telescope In Italy, A Prototype To Advance The Search For Life On Exoplanets
[IAC] The Instituto de Astrofísica de Canarias (IAC) has presented the progress made on the SELF (Small ExoLife Finder) telescope at the international Charting the Future of Stellar and Exoplanet […]
Posted inExoplanets, -moons, -comets
Atmospheric Dynamics And Variability Of Periodically Irradiated Tidally Locked Planets
[astro-ph.EP] Time-variable stellar heating may create new climate states, such as permanently hot or cold hemispheres, on asynchronous planets. Planets on eccentric orbits, circumbinary planets and planets on polar orbits […]
![Graphical Abstract -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Space-Journey-Beyond-Earth.jpg?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
Space Journey Beyond Earth: Exploring The Properties Of Exoplanets And Multi-planetary Systems
[astro-ph.EP]. In contrast to the observed exoplanet diversity, planets within many multi-planetary systems exhibit intra-system similarities in their radii, masses, and orbital spacings.
![D.2: Transit signals recovery analysis in the TESS light curve of TOI-210. TOI-210 b is shown in gold at its period of 9.01 days. Candidate planets at 2.15 and 3.76 days tentatively detected in the NIRPS RVs are indicated as lower limits, with arrows extending from minimum (iron density) to realistic (Earth density) radii based on their minimum masses. The expected transit depths fall within the TESS sensitivity, suggesting that if these RV signals are planets, they are unlikely to be transiting. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/A-temperate.png?resize=1200%2C713&ssl=1)
Posted inExoplanets, -moons, -comets
A Temperate Sub-Neptune Transiting The M4 Dwarf TOI-210 Identified By NIRPS And TESS — Uncovering Hidden M-dwarf Planetary Systems In The Near-infrared
[astro-ph.EP] Super-Earths and sub-Neptunes dominate the exoplanet population, yet their compositions, formation mechanisms, and capability of retaining atmospheres remain poorly understood. M-type stars offer a unique opportunity to investigate these […]
Posted inAstrogeology
Our Solar System Chose Fire Over Ice To Build Its First Bodies
[Yale University] When the solar system first took up the task of building solid bodies — such as planets, moons, and protoplanets — it basically had a choice between two […]